From: John Lenton <john.lenton@canonical.com>
To: Jan Kara <jack@suse.cz>
Cc: Kai-Heng Feng <kaihengfeng@me.com>, Jens Axboe <axboe@kernel.dk>,
Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>,
linux-block@vger.kernel.org,
jean-baptiste.lallement@canonical.com
Subject: Re: [PATCH] loop: Don't change loop device under exclusive opener
Date: Tue, 30 Jul 2019 10:36:59 +0100 [thread overview]
Message-ID: <CAL1QPZQWDx2YEAP168C+Eb4g4DmGg8eOBoOqkbUOBKTMDc9gjg@mail.gmail.com> (raw)
In-Reply-To: <20190730092939.GB28829@quack2.suse.cz>
On Tue, 30 Jul 2019 at 10:29, Jan Kara <jack@suse.cz> wrote:
>
> Thanks for the notice and the references. What's your version of
> util-linux? What your test script does is indeed racy. You have there:
>
> echo Running:
> for i in {a..z}{a..z}; do
> mount $i.squash /mnt/$i &
> done
>
> So all mount(8) commands will run in parallel and race to setup loop
> devices with LOOP_SET_FD and mount them. However util-linux (at least in
> the current version) seems to handle EBUSY from LOOP_SET_FD just fine and
> retries with the new loop device. So at this point I don't see why the patch
> makes difference... I guess I'll need to reproduce and see what's going on
> in detail.
We've observed this in arch with util-linux 2.34, and ubuntu 19.10
(eoan ermine) with util-linux 2.33.
just to be clear, the initial reports didn't involve a zany loop of
mounts, but were triggered by effectively the same thing as systemd
booted a system with a lot of snaps. The reroducer tries to makes
things simpler to reproduce :-). FWIW, systemd versions were 244 and
242 for those systems, respectively.
next prev parent reply other threads:[~2019-07-30 9:37 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-16 14:01 [PATCH] loop: Don't change loop device under exclusive opener Jan Kara
2019-05-16 20:44 ` Jens Axboe
2019-05-27 12:29 ` Jan Kara
2019-05-27 13:34 ` Jens Axboe
2019-07-18 8:15 ` Kai-Heng Feng
2019-07-30 9:29 ` Jan Kara
2019-07-30 9:36 ` John Lenton [this message]
2019-07-30 10:16 ` Jan Kara
2019-07-30 13:36 ` Jan Kara
2019-07-30 17:59 ` Kai-Heng Feng
2019-07-30 19:17 ` Jens Axboe
2019-07-30 21:11 ` John Lenton
2019-07-31 8:56 ` Jan Kara
2019-08-05 16:41 ` Bart Van Assche
2019-08-05 21:01 ` Tetsuo Handa
2019-08-07 9:45 ` Jan Kara
2019-08-07 18:45 ` Bart Van Assche
2019-08-08 13:37 ` Jens Axboe
2019-07-30 10:16 ` Tetsuo Handa
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